【作者】 李云；

【导师】 努丽燕娜；

【作者基本信息】 上海交通大学 ， 化学工程与技术， 2010， 硕士

【摘要】 跟二次锂电池比起来,二次镁电池具有价格低廉、安全性高的优点,是一种不错的高能量密度电池。这方面的研究主要集中于可实现镁可逆沉积的非水电解液以及可嵌入Mg2+的正极材料。在本文章中主要通过高温固相法和熔盐法制备并研究了聚阴离子型MgxMySiO4(M=Fe、Ni,x+y=2)作为二次镁电池的新型正极材料,并对硅酸铁镁材料做了较深入的研究,具体涉及到合成温度(800℃、900℃以及1000℃)、熔盐比例(KCl:MgO=2:1、4:1、6:1和8:1)以及粘结剂(PVDF、PTFE及SBR)对材料电化学性能的影响。另外,本文章通过采用简单的熔盐方法,对硅酸铁镁材料进行了过渡金属锰的掺杂,在KCl熔盐介质中800℃、900℃以及1000℃不同烧结温度下制备了可充镁电池正极材料Mg0.75Mn0.15Fe1.1SiO4。将上述所制备材料作为活性物质制作成极片,以0.25 mol/L Mg(AlCl2EtBu)2/THF为电解液,镁条为对电极,组装成CR2016扣式电池。并在C/10下进行充放电实验,发现在900oC下、熔盐比例为4:1时制备的硅酸铁镁由于材料晶型、颗粒粒径比较理想,电化学性能较好。而用PVDF作为粘结剂的上述材料,由于其橡胶性较好,相对于其他所研究的粘结剂而言有比较好的的电化学循环稳定性。更多还原

【Abstract】 Magnesium batteries may be a candidate of high energy density batteries comparable with lithium batteries due to cheaper raw material costs and less danger of magnesium than lithium. Researches about rechargeable magnesium batteries focus on non-aqueous electrolyte systems, from which magnesium can be reversibly deposited and dissolved, and cathode materials that can reversibly intercalate and de-intercalate magnesium ions.In this work, we have prepared novel cathode materials MgxMySiO(4M=Fe、Ni,x+y=2) for rechargeable magnesium battery by high temperature solid-state reaction and molten salt method. The heating temperature (800℃, 900℃and 1000℃), ratio of molten salt (KCl: MgO= 2:1, 4:1, 6:1 and 8:1) as well as binders (PVDF, PTFE and SBR) on the material structure, morphlogy and electrochemical performance have been studied detailedly. Moreover, Mg0.75Mn0.15Fe1.1SiO4 was prepared by doping Mn into MgFeSiO4 using the molten salt method and electrochemical performance was further studied.Electrochemical performance of the materials was tested via CR2016 coin cells with magnesium ribbon counter electrode, 0.25 mol/L Mg(AlCl2EtBu)2/THF electrolyte. At a rate of C/10, the cathode material prepared under the temperature of 900℃,and at the ratio of molten salt at 4:1 exhibited good electrochemical performance due to fine crystallite structure and small size. Moreover, the electrode using PVDF as binder had good cycling stability due to the wide expansion thickness.更多还原